JPH08138472A - Structure of push button mounting hole and structure of molding die for push button mounting hole - Google Patents

Abstract

PURPOSE: To stabilize installation of a push button and to prevent an operation of the push button from being inhibited by suppressing a burr within a space C. CONSTITUTION: In a push button mounting hole 4 arranged in a synthetic resin case body 3, an inside face 402 from a case body back face 302 side of the mounting hole 4 to the middle is spread further over the whole circumference than an inside face 401 from a front face 301 side to the middle, and a stepped plane 403 is formed between the inside face 402 and the inside face 401, while at the edge of the stepped plane 403, a burr 404 in molding is generated in the sliding direction of the push button, and the burr 404 is suppressed within the height of a clearance C formed of the side face of the push button, the inside face 402, and the stepped plane 403, when the push button is mounted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a push button of an electric device having a push button operation part, and particularly to a case where the operation part of the housing of the electric device is made of synthetic resin. The present invention relates to a structure of a push button mounting hole of a portion and a molding die structure of the push button mounting hole portion.

[0002]

2. Description of the Related Art For example, an electric device such as a telephone has a push button such as a dial button in its operation portion, and the push button is mounted in a hole penetrating through the operation portion of a housing. This hole is called a mounting hole.

When the housing or the panel of its operating portion is made of synthetic resin, conventionally, a molding die having a structure as shown in FIG. 4 (A) or (B) is used.

The mold shown in FIG. 4A has a mold structure (hereinafter, referred to as a mold structure) having a columnar body 111 whose shape matches the shape of the push button mounting hole.
It is called the first type structure. ) 11 and a plate-shaped mold structure (hereinafter referred to as a second mold structure) 12 in combination, and FIG.
The mold shown in (B) is a first mold structure 11 similar to the first mold structure 11 shown in FIG. 4 (A), and a columnar body 1 of the first mold structure 11.
Second type structure 1 having a recess 121 into which the tip of 11 is fitted
2 in combination with the first and second type structures 11, 1
When the two are combined, the molten synthetic resin flows into the molding space A formed around the columnar body 111, and when it is cured, the housing has a mounting hole for a push button (or an operation unit panel, hereinafter referred to as a housing). .) Is molded.

When molding the casing, pressure is applied to the molding space A so that the melted synthetic resin reaches the details of the molding space A, but the weld (wrinkle-like scratches) appearing on the surface of the casing, especially around the mounting holes. Therefore, the above pressure is set to a considerably high value in order to minimize as much as possible due to shrinkage of the synthetic resin during curing. As a result, the synthetic resin enters into a slight gap B in the contact portion between the first mold structure 11 and the second mold structure 12, whereby the housing 13 formed by the mold having the structure shown in FIG. FIG. 4 (C) or (D)
As shown in FIG. 4, horizontal burrs 132 are formed at the lower edge or the upper edge of the mounting hole 131 of the push button 14, and FIG.
In the housing 13 molded by the mold having the structure shown in (B),
As shown in FIG. 4 (E) or (F), the push button mounting hole 1
Vertical burrs 132 are formed on the lower edge periphery or the upper edge periphery of 31. The housing 13 shown in FIGS. 4C and 4E is
The surface side thereof is formed by the first mold structure 11 (that is, the first mold structure 11 is the cavity side and the second mold structure 12 is the core side), and FIGS. 4D and 4F. The surface of the housing 13 shown in FIG.
(That is, the first mold assembly 1)
1 is the core side, and the second mold structure 12 is the cavity side. ).

[0006]

The housing 13 molded by the above-mentioned conventional mold has the push button 14 as described above.
Since burrs 132 are generated horizontally or vertically on the periphery of the device hole 131 of FIG. 1, the housing 1 having the structure shown in FIG.
In No. 3, the push button 14 cannot be mounted in the mounting hole 131 (when the burr 132 is large), or even if it can be mounted, the burr 132 may hit the side surface of the push button and the push button operation may not be performed smoothly. Very strong (When the push button 14 is pressed, the burr 132 is formed on the side surface of the push button 14.
Cannot be returned to the original position due to being caught).

Further, in the case 13 having the structure shown in FIG. 4 (E), when the push button 14 is attached to the attachment hole 131,
The burrs 132 come into contact with the hem portion 141 provided at the lower end of the push button 14 to prevent the push button 14 from coming off.
4 cannot be mounted in a predetermined position (position regulated by the back surface of the housing 13) in a predetermined posture, and the burr 132
If the difference in height between the left and right is extreme, the mounting posture of the push button 14 is extremely tilted, and the upper end of the push button 14 contacts the inner surface of the mounting hole 131 to operate the push button 14 as described above. May not be smooth.

Further, in the case 13 having the structure shown in FIG. 3 (F), since the burr 132 stands up on the front surface side of the case 13, when the push button 14 is pressed, the burr 132 hits a finger and causes discomfort. Not only there, but sometimes Bali 13
There is also the risk of being scratched by two sharp edges.

In any case, the occurrence of the burr 132 is not preferable. However, since it is impossible to completely eliminate the burr 132, efforts have conventionally been made to keep the occurrence of the burr 132 within an allowable range. That is, it is necessary to control the melting temperature of the synthetic resin at the time of molding, the temperature control of the mold, the applied pressure control, etc.
Moreover, these management conditions are always influenced by changes in the environmental conditions of the outer periphery of the mold (seasonal or daily changes in temperature, humidity, etc.), so it is necessary to adjust the molding conditions at any time.
Requires extremely advanced technology and know-how in the molding process.

The present invention has been proposed to solve the above problems. Even if a burr occurs, it does not adversely affect the operation of the push button or the mounting posture, and is a safe push button mounting hole. It is an object of the present invention to obtain the above structure and the molding die structure of the push button mounting hole portion.

[0011]

In order to solve the above-mentioned problems, the present invention provides a mounting hole for a push button provided in an operating portion of a housing, and an inner side surface extending from the middle thereof to the back side of the operating portion.
By having a shape that extends over the entire circumference from the inner side surface from the middle to the surface side of the operation portion, between the side surface of the push button and the inner side surface of the mounting hole in a state where the push button is fitted, A space that does not penetrate to the front surface side of the operation portion is formed over the entire periphery thereof, and in the molding process of the housing, burrs that occur in the sliding direction of the push button are formed at the middle peripheral edge of the mounting hole. The structure is such that it fits within the height of the space.

Further, the molding die for the push button mounting hole portion having the above structure has a first die structure having a columnar body whose peripheral shape matches the planar shape of the operation portion surface side of the push button mounting hole, and the first die structure. And a second mold structure having a recess of the same shape, and the inner wall surface of the recess is flat over the entire circumference of the upper edge of the recess of the second mold structure. The structure is such that a jetty having a height lower than that of the molding space around the columnar body is formed.

[0013]

The first mold assembly (hereinafter referred to as the first mold assembly) is fitted with the tip end portion of the columnar body into the recess of the second mold assembly (hereinafter referred to as the second mold assembly), and the assembly is completed. Molten synthetic resin is poured into a molding space formed between the first mold structure and the second mold structure, and the synthetic resin is cured while applying a predetermined pressure to mold the housing. At this time, the second
Since the synthetic resin in this part is removed by the jetty provided around the concave part of the mold structure, it is formed to be wider than the front side of the operation part from the middle of the mounting hole to the back side of the operation part. A portion is a space formed between the push button and the side surface of the push button when the push button is mounted.

Further, the surface where the first mold structure and the second mold structure abut against each other is a surface perpendicular to the plane of the housing at the abutting portion between the columnar body and the jetty (recess), so that at the time of molding. Burrs occur in the sliding direction of the push button at the upper edge of the space. This eliminates the sliding failure of the push button due to burrs.

Further, the height of the space formed by the frame is set to be higher than the predicted height of the burr, so that the burr generated in the mounting hole is set in the space. The mounting posture of the push button is stable, and the push button is mounted at a predetermined position according to the standard.

[0016]

1 to 3 are views for explaining an embodiment of the present invention, FIG. 1 is a perspective view of a mounting hole portion of a push button provided in an operating portion of a housing, and FIG. 2 is a mounting hole. FIG. 3 is a sectional view when a push button is mounted, and FIG. 3 is a sectional view of a mounting hole forming portion of a molding die. Note that FIG. 1 is drawn in a partially cut state with the back surface side of the housing facing upward, and FIGS. 2 and 3 are drawn with the front surface side of the housing facing upward.

For easy understanding, the structure of the molding die of the mounting hole portion of the push button according to the embodiment will be described with reference to FIG.

As shown in FIG. 3, the mold according to the embodiment is
A combination of the first mold structure 1 and the second mold structure 2,
The mold structure 1 is used as a cavity side for molding the front surface side of the housing 3, and the second mold structure 2 is used as a core side for molding the back surface side of the housing 3. Hereinafter, the first mold structure 1 is referred to as a cavity, and the second
The mold structure 2 will be described as a core.

The cavity 1 has a peripheral shape matching the plane shape (rectangle in the embodiment) of the operation portion surface side of the mounting hole 4 (see FIG. 1 or 2) of the push button 5 provided in the operation portion of the housing 3. Columnar body (columnar body having a rectangular cross section in the embodiment) 101
Is integrally provided with the surface forming section 102 for forming the surface of the operation section, and the structure of the cavity 1 itself is the same as the structure of the first mold assembly 11 shown in FIG. Is the same.

Further, the core 2 is provided with a recess 201 having the same shape (rectangular in the embodiment) as the tip 101A of the columnar body 101 of the cavity 1, and the entire upper end edge portion of the recess 201 is provided. A jetty 202 is provided. The jetty 202 has a rectangular frame shape corresponding to the shape of the recess 201.

The inner side surface 202A of the jetty 202 is flat and forms the inner wall surface of the recess 201, and the height from the back surface molding portion 203 for molding the back surface of the operation portion is the molding space A. It is set lower than the height of (the molding space around the columnar body 101).

In the above structure, the bottom portion 2 of the recess 201 is
In the structure shown in FIG. 3, 01A is lower than the back surface molding portion 203, but may be at the same position as or higher than the back surface molding portion 203, and further, the bottom portion 201A itself may not be present (that is, The recess 201 may penetrate to the back surface side of the core 2.). The point is that the tip portion 101A of the columnar body 101 is fitted into the recess 201 to form the cavity 1
And the core 2 are combined, the abutment surface of the columnar body 101 and the recess 201 is perpendicular to the plane of the back surface molding portion 203, and the abutment surface has a length of a burr described later. It is sufficient if the length is sufficient. In addition,
In FIG. 3, the gap B is drawn as if it were formed wide on the abutting surface, but the gap B is actually very small.

The method of molding the housing by the above-described mold will be briefly described. The cavity 1 and the core 2
3 is combined with the state shown in FIG. 3, and the molten synthetic resin is poured into the molding space A formed thereby while applying pressure to the molding space A, and the curing of the synthetic resin is waited. After the synthetic resin is hardened, the cavity 1 and the core 2 are separated vertically in FIG. 3, and the synthetic resin after hardening, that is, the housing 3
Take out. In the above molding process, the synthetic resin flows into the slight gap B formed in the abutting surface between the columnar body 101 of the cavity 1 and the recess 201 of the core 2, and this becomes a burr. That is, the push-button mounting hole 4 is formed into a shape as shown in FIG.

The present invention can be practiced with the first mold structure 1 on the core side and the second mold structure 2 on the cavity side.

Next, the structure of the mounting hole 4 of the push button 5 and the state in which the push button 5 is mounted in the mounting hole 4 will be described with reference to FIGS.

As shown in FIG. 1, the mounting hole 4 has a hole (rectangular shape in the embodiment) whose shape on the surface 301 side (lower side in FIG. 1) of the housing 3 matches the shape of the operating portion of the push button 5. The shape of the formed housing 3 on the back surface 302 side (upper side in FIG. 1) is formed by a hole penetrating to the front and back formed in a hole formed by expanding the hole on the front surface 301 side over the entire circumference thereof.

The inner side surface 401 of the mounting hole 4 from the front surface 301 side to the middle and the inner side surface 4 of the rear surface 302 side to the middle.
No. 02 is formed substantially perpendicular to the plane of the housing 3 (usually, there is a slight inclination that spreads in the direction of pulling out the mold in order to facilitate separation from the mold), and mounting. A step plane 403 based on the dimensional difference between the holes on the front surface 301 side and the back surface 302 side of the housing 3 is formed in the middle of the hole 4, and the push button 5 is fitted into the mounting hole 4 as shown in FIG. When retracted, the inner side surface 402 and the side surface 5 of the push button 5
01, a space C is formed over the entire circumference, and the space C is closed by the step plane 403 and does not penetrate the surface 301 side of the housing 3.

As is clear from the description of the mold, the burr 404 is formed vertically on the edge portion of the step plane 403 toward the back surface 302 side. The size of the space C is set so that the height h of the burr 404 is within the height H of the space C. The size of the space C is set by setting the height of the jetty 202 provided in the core 2 of the mold.

When the push button 5 is mounted in the mounting hole 4 described above, the state shown in FIG. 2 is obtained. The push button 5 is elastically biased in a counter-pressing direction by a switch (not shown) which is normally operated by operating the push button 5, and when the push button 5 is not operated, its hem portion 502 is the back surface 30 of the housing 3.
It is pushed upward in FIG. 2 until it abuts 2 (which is an operation regulating surface). FIG. 2 shows this state.

The burr 404 is formed on the same plane as the inner side surface 401 of the mounting hole 4 (that is, occurs in the sliding direction of the push button 5) as described above, and the height h thereof is the height of the space C. Since it is lower than H, the burr 404 does not catch on the side surface 501 of the push button 5 or hit the hem 502 as shown in FIG. Therefore, the sliding movement of the push button 5 during operation is smooth, and the push button 5 is correctly mounted in the mounting hole 4 in a defined posture.

[0031]

As described above, according to the present invention, a space is formed on the inner side surface from the middle of the push button mounting hole to the rear surface side of the housing, and when the housing is molded, the combined surface of the mold cavity and the core is formed. The burr generated in the above space fits within the height of the space in the sliding direction of the push button in the space, and the burr protrudes on the side surface of the push button or the operation restricting surface of the push button ( Without protruding from the back surface of the housing or from the operation surface (the surface of the housing 3)
The operation of the push button is smooth, you can mount the push button correctly,
In addition, a secure push button mounting hole structure can be obtained.

Further, the present invention allows the occurrence of burrs,
Since the inconvenience caused by the burr is eliminated by the structure of the mounting hole, the molding conditions such as the applied pressure and temperature at the time of molding the housing (or the operation part) become gentle, and the management of the synthetic resin molding process becomes easier. It will be easy.

[Brief description of drawings]

FIG. 1 is a perspective view of a mounting hole according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state in which a push button is attached to an attachment hole according to the embodiment of the present invention.

FIG. 3 is a sectional view of a molding die according to an embodiment of the present invention.

4A and 4B are cross-sectional views of a conventional mold,
(C)-(F) is a cross-sectional view of a state in which a push button is mounted in the mounting hole of the conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st type | mold structure (cavity) 2 ... 2nd type | mold structure (core) 3 ... Enclosure 4 ... Mounting hole 5 ... Push button 101 ... Columnar body 201 ... Recesses 202 ... Jetty 401,402 ... Inner side surface 403 ... Step plane 404 ... Burr 501 ... Side surface 502 ... Bottom A ... Molding space B ... Gap C ... Space

Claims (2)

[Claims] 1. A mounting hole for the push button which is formed through at least one of the front and back sides of the operating section of a device in which at least the operating section of the housing is made of synthetic resin and the push button is slidably mounted on the operating section. The structure extending from the middle of the height direction of the inner surface of the mounting hole to the back side of the operating portion over the entire circumference from the middle of the mounting hole to the front surface side of the operating portion. By making the hole diameter wider, a space that does not penetrate to the front surface side of the operation section is formed between the side surface of the push button and the inner side surface of the mounting hole in the state where the push button is fitted, over the entire circumference thereof. In the molding process of the housing, the burr generated in the sliding direction of the push button at the middle edge of the mounting hole is set within the height of the space. Pore structure. 2. A first mold structure having a columnar body whose peripheral shape matches the planar shape of the operation portion surface side of the mounting hole of the push button, and a recess having the same shape as the tip end of the columnar body of the first mold structure. And a second mold structure having the above-mentioned second mold structure, the inner wall surface of the recess is formed flat over the entire circumference of the upper edge portion of the recess of the second mold structure, and the periphery of the columnar body is molded. A molding die structure of a push button device hole portion forming a jetty having a height lower than the height of a space.